


make sure you kiss your knuckles before you punch me in the face

by silklace



Category: It's Always Sunny in Philadelphia
Genre: Angst and Porn, Crossdressing, Dirty Talk, Internalized Homophobia, Internalized Misogyny, Light BDSM, M/M, Not Actually Unrequited Love, Plot What Plot/Porn Without Plot, Unsafe Sex, truly gratuitous use of "baby boy"
Language: English
Status: Completed
Published: 2017-05-12
Updated: 2017-05-12
Packaged: 2018-10-31 00:29:35
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,348
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10888119
Author URL: https://archiveofourown.org/users/silklace/pseuds/silklace
Summary: “Uh,” he says. He scratches the back of his head, feeling heat bloom across his cheeks. Jesus Christ. “Why you still wearing that?”Or, Dennis wears a dress, Mac rationalizes this as Not Gay, and the rest of the Gang pretends they can't hear the sounds coming from the office.





	make sure you kiss your knuckles before you punch me in the face

**Author's Note:**

> This is a coda of sorts to The Aluminum Monster vs. Fatty Magoo, written about ten years late, so apologies if this has been done before/to death. For those who don't remember an episode that aired in the late 2000s, all you really need to know is [this](http://vignette3.wikia.nocookie.net/itsalwayssunny/images/2/2a/Dennis%27_perfect_woman.jpg/revision/latest?cb=20120529074448). 
> 
> Please heed the warnings; this is ~4,000 words of pure filth. With a side of fucked up angst, as only IASIP can bring to the table. 
> 
> Title is from Twin Size Mattress by The Front Bottoms, a very good and a very macdennis song.

“I got it, Frank, I got it, goddamn, I heard you the first seven million --,” he’s calling over his shoulder as the door swings wide behind his kick, cardboard boxes filled with the sweatshop materials piled high in his arms (“That’s an investment,” Frank had said knowingly, patting the top of one box where the steam whistle was propped at an ugly angle, “Bring all this shit up and store it in the ceiling, we don’t know when it might come in handy again, you understand?”), but the rest of the sentence dies in his throat when he sees what – or rather, who – is inside the otherwise empty office, hip knocked out to one side and legs crossed at the knee. The door swings back behind him and, on some instinct, Mac kicks it closed with the sole of his shoe. He drops the stack of boxes in front of it. 

“Uh,” he says. He scratches the back of his head, feeling heat bloom across his cheeks. Jesus Christ. “Why you still wearing that?”

“I was waiting for you,” Dennis counters, smirking and leaning back against the desk with one hand, the movement a little uncoordinated so that his mouth goes tight and pinched at the edges. The dress hugs and ripples across his ribs as he shifts, the pearly latex shimmering in the dim lights of the back office. Dennis uncrosses and re-crosses his legs, giving Mac an easy view of the dark space between his thighs, but Mac doesn’t look, he’s not like that, not interested in what’s between a man’s legs. 

“That’s weird, man.” He takes a step forward. He can hear Charlie and Dee arguing about something at the bar, right outside the door. “I don’t –,” he starts, but he doesn’t get to explain what he doesn’t do, because Dennis levels him with a glare and says, “Shut the fuck up, Mac.”

“Yeah,” Mac grunts. He lets his gaze drop, takes in the way the stretch of the latex dress carves out Dennis’ hips and ribs, the smooth shape of his white, bare thighs. The dress is so short that Mac can almost see where the tops of his legs meet again in a soft vee-shape, not that he’s familiar with what Dennis looks like when he’s stripped of his clothes, laid out with his legs parted. Mac suddenly wants to put his face into the crook of his elbow, blacken out the rest of the world, find Charlie and something toxic to huff, but he also can’t look away. 

“You gonna just stand there with your dick in your hand or you gonna do something about this,” Dennis snaps, the tight pitch of his voice a strange contrast to the languid way he’s still leaning back on his hands and parting his thighs, legs draped over the edge of the desk like liquid silver. His chest is heaving a little, and Mac notices; the huge, latex covered tits are kind of hard to ignore.

“Fuck you, Dennis,” Mac says, but he’s got one hand creeping up under his own t-shirt, blunt nails trailing across his belly. He takes another step forward. 

“That’s more like it,” Dennis breathes, and he looks down at his own chest, the fake breasts cartoonish and perfectly rounded. His mouth falls into a loose shape. “I’d let you fuck them,” he says, and he laughs with a sound that’s not really a laugh but that mimics and mocks one. “If they were real,” he adds, glancing between his chest and Mac’s face, “I’d get down on my knees in front of you and bounce my tits over your dick.”

And that works – the words that had been batting around in Mac’s head and keeping him from crossing the room and palming the side of Dennis’ face as soon as he saw him blink out and disappear from his brain. There’s nothing gay about tits; no one could see him pushing his cock through the gorgeous cleft of Dennis’ cleavage and call him a sissy, a faggot. He knows men – real men, powerful men -- do that to women, has seen it in the porn flicks they watch together, the ones that make the muscles on Dennis’ thighs bunch as he works his hand over himself, ‘cause Dennis loves big tits, the huger and the faker the better. 

“Yeah,” Mac says, “that’s right, I’d love that.” He’s close enough now that he can see the faint smear of red around Dennis’ mouth, as if he’d wiped off the lipstick from earlier with a napkin in the car on his way back to the bar. Mac wonders if he went and checked right now if he’d find a crumpled, brown Dunkin Donuts napkin with smudges of red lipstick in the cup holder of Dennis’ car or the foot well of the passenger side, as if he’d thought about this, planned ahead, planned to put his mouth to use tonight. Mac shivers. 

Dennis stretches out one long leg and hooks it around the back of Mac’s knees, forces him to close the distance. “I know you would, baby boy, I know you would.” His fingers find Mac’s face and cup his jaw. He’s breathing hard now. “I’d get them all wet for you, use some of that mineral oil we’ve got, and you’d fuck them so good, your dick sliding in and out,” he gasps, words rolling over his tongue and lips like black oil slicked across water, and Mac’s brain is starting to stutter and shift away from him, so that all he can feel is the sear of Dennis’ hips canted wide around him, the hot gust of his breath as he shifts up to whisper filth into Mac’s ear. “Your dick, fuck - Mac, your dick is so big it wouldn’t even be a challenge for me to suck on the head at the same time, so that you’d be fucking my tits and my mouth all at once, huh big boy?” 

Mac groans, puts his hands around Dennis’ bony, familiar hips. “Fuck, yeah,” he says. His cock is a hard, firm line in the front of his pants, and he pushes up against the gap created by the skirt spread across Dennis’ thighs. He wants to peel back the latex and fuck up into that gap, let his cock press into the warm, tight heat of Dennis’ body, but he knows this mood of Dennis’, knows that the pace they set tonight is going to be dictated by Dennis, who is at his most frantic and fragile when he’s like this, all wound energy and a frenetic desire to wreck himself against the sharp gleam of Mac’s unyielding presence. 

Dennis’ hand is claw-like around Mac’s jaw, his mouth bruised and red and just barely grazing over Mac’s cheek, the side of his neck. “You gonna fuck me tonight, big boy,” Dennis gasps, a smirk hiding somewhere in those words. “You gonna take your cock and split me open?”

They don’t talk about this, Mac thinks, alarm bells starting to take up clatter in his brain again. Dennis is breaking the unspoken rule, and Mac feels a frisson of anger and heat curl around his fist. He wants to punch a wall, or Dennis’ smooth, pretty face. But Dennis is still smirking, and Mac thinks he knows he’s broken the rule, smashed it open wide and bleeding, and Mac suddenly remembers something about merciful gods. 

Dennis runs his nose along the side of Mac’s jaw, up along his cheek bone. “Hmm?” he murmurs, and it would almost be tender if it weren’t Dennis. 

Mac grunts and shifts his thumbs so they slide up the smooth, hairless skin of Dennis’ thighs and slot under the plastic material of the dress. He wants to pull Dennis’ mouth down to meet his own and kiss him, but he can’t seem to make his body do what he wants it to tonight, or else he would have turned and left the minute this whole thing started. He hums, wordlessly, into the skin of Dennis’ shoulder, sliding his hands around to rub over the swell of his ass, but Dennis stills and presses the sole of one high heeled foot against Mac’s hip. He narrows his eyes. “I want to fucking hear you, Mac.” 

Mac grips his booted ankle, and the latex makes an unpleasant sound. A muscle clenches in Dennis’ jaw. “Start talking, you fuck, or I get up and walk out.”

He will, Mac knows he will, he’s done it before one night not too long ago, when he’d been stretched out underneath Mac on his bed, and Mac had been kissing him soft and slow and agonizing for the last half hour, fingers gently cradling the back of his head. Mac had pulled back, and the moonlight was soft on Dennis’ face and Mac had smiled, felt like his ribs were being pulled open inside his chest, and something had flickered and died on Dennis’ face until he was shoving Mac aside wordlessly, slamming the door of Mac’s bedroom open and leaving the apartment, still shirtless, bite marks climbing up the column of his neck. He’d come back an hour or two later, and Mac could smell the midnight air on his skin, and they hadn’t talked about it. 

Now, Mac grips the fine bones of Dennis’ ankle until Dennis winces and releases a breath in one long, easy motion, but his knee is still pulled up and coiled, like a gun cocked and ready to fire. 

Gently, Mac twists his hand so that Dennis’ ankle is notched out to the side and then he’s crowding close again, hooking Dennis’ leg over his arm and pressing him back into the desk. Eyes steely and unrelenting, Dennis lowers to his elbows and then no more. “Tell me you want to fuck me,” he hisses, fingers bony and splayed on the desk beside him. “You always said I’d look good with a pair of tits, isn’t that right, man?” His face looks carved from ice and lit up within, and Mac again wants to kiss him, or punch him, or find a fucking rosary to press into the soft skin of his throat. 

“You’re such a slut,” he says instead, and he hitches Dennis’ legs up a little higher on his arms, so that his hips are split wide and his legs canted open. He looks not unlike a fucked up Barbie-doll that someone’s smashed into the pavement, legs kicked out at odd angles. “Such a fucking slut,” he breathes, leaning down to close his mouth over the jut of his Adam’s apple. “Even if you had a pussy, I’d bend you over and fuck you in the ass,” he says, and Dennis chokes, head rolling back on his neck. Mac untangles his fingers and pushes them up under Dennis’ skirt. His fingers bump lace and the hot line of Dennis’ cock trapped under too-tight panties. 

He feels a little dizzy, and his words are shaky, but he bends again and mouths them into the base of Dennis’ throat. “You’re such a whore,” he says, working his fingers around the lace and pushing it to the side so that he can run his hands over the smooth cleft of Dennis’ ass. He wants to put his cock there, make Dennis squirm and bounce on it. “A fucking whore,” he repeats, mouth sticky against hot skin; he can feel the fake tits bumping against his chin and in a fit of inspiration he leans down and puts his face between the mounds like he’s seen other men do in pornos. Dennis keens. 

“Fuck,” he says, breathless, hips jumping off the desk. “Fuck, Mac, fuck, I wish I had tits for you to suck on, so I could see you with your whole mouth open against my tit, tonguing me.”

Mac raises his head up and presses his lips to the underside of Dennis’ chin; it’s not really a kiss. “It’s okay,” he admits, truthfully, and Dennis’ laugh is a little strangled. He leans his head back, though, baring his throat again. Every time Mac pulls a bit of flesh between his teeth, Dennis makes a choked off hitching noise in the back of his throat, so Mac keeps on doing it, leaving purpling marks in his wake. 

“I’d fuck you until you couldn’t walk,” he says, shuddering, the words feeling strange in his mouth. He’s never said anything like that before, not even to Dennis, not even when he’s in one of his moods where they fuck angry, Dennis riding him silently, head thrown back, only speaking to tell Mac to slap him across the face and this time he wants to fucking feel it. But Dennis shivers and hisses, “Yes, fuck, yes,” throwing his hips back against Mac’s hand, begging wordlessly to be finger fucked, so Mac continues. 

“Yeah,” he grunts, rolling his own hips against the underside of Dennis’ thigh. “I’d fuck your ass until you came, squeezing around my dick, and I’d want to come, too, but I’d pull out and turn you around so I could shove my cock in your mouth. I wanna come down your throat, watch you gag on it.”

Dennis’ mouth stretches into a languid smile, then, and Mac can see his pulse rabbiting in his throat. “Put your fingers in me,” he says, and his voice sounds raw, like he’s been screaming. 

Mac presses his mouth to the side of Dennis’ forehead, just above his temple. It’s not really a kiss. 

“I don’t,” he bites out, “We don’t have any lube.”

“I’m good, man,” Dennis says, eyes hooded and pupils blown wide - he looks like he could be sitting on a throne, smirking, holding a secret between his lips, one twitch of his finger and men fall on their swords. Mac wonders if, in this fantasy, he’s the one who submits to the press of a blade against his throat, or is he the one just out of the picture, standing to the side of the throne, fingers curled on the back of a neck, whispering about men who are gods in disguise.

“I’m good,” Dennis repeats, a little urgently, his face less sure, more earnest, and Mac remembers there are no thrones here and, in reality, Dennis’ knees are up by his ears, and there’s a red, angry looking crease along the backs of his thighs where the edge of the desk bit into his skin. 

“No, fuck, Dennis, no, I’m not going in dry – that definitely does not work.” He knows, because they’d tried once, when Dennis had come home one night, smelling like stale beer and unfamiliar cologne, a faint, mottled mark high up on his throat and Mac had seen red, something pulling apart in him like glass melting against hot iron. 

“I did it myself,” Dennis grits out, the flush crawling from his throat up to the tips of his ears. “I -,” his voice cracks and he tries again, looking painfully embarrassed and somehow unashamed all at once. “I wanted to be ready.”

“Oh.” Mac says. The skin behind Dennis’ knees is soft and velvet smooth, and Mac resists the urge to put his mouth there. “Oh,” he says again. His understanding of tonight rewrites itself again. 

“So,” Dennis says, drawing out the word, something determined flickering back into his eyes. He hauls himself up so his mouth brushes against Mac’s lips as he speaks. “I’m ready,” he breathes. “Fuck me with your fingers, big boy, I wanna fucking feel you.” He takes Mac’s wrist and guides it between his legs, breath hitching. “I’m so fucking wet for you,” he shudders out, and he’s pulling the lace aside again. 

Mac takes two fingers and lines them up against his hole, pressing, circling, pushing until he’s sliding smoothly inside, up to his knuckles, further, until his hand is pressed tightly to the circle of Dennis’ clenching hole and he starts fucking his fingers in, bones and bodies awkward but thrilling, and there’s a cramp already starting up in his forearm, but Dennis is circling his hips and moving with Mac’s fingers, so that they’re one motion, stuttery, connected, Dennis’ breath hot on his cheek, telling him he wants it, he wants it so bad he can fucking taste it, he wants Mac to open him up and crawl inside of him. 

“I got you,” Mac whispers, and it’s so quiet he’s not sure Dennis hears him, but he adds another finger and feels Dennis’ shocked pleasure thrum through him and that’s good, Mac thinks, that’s good. He rubs his cock, a little desperately, against the side of Dennis’ body, and he’s so hard he knows he’s not going to last long at all, wonders a little distractedly if Dennis will make fun of him for it, but he shoves that thought aside when Dennis, gasping and unraveling as Mac fucks him with three fingers, seems to have some clarity in the midst of his lust-addled haze and reaches to undo Mac’s pants, wraps his hand around the base of Mac’s cock so that the dark, flushed head just bumps over Dennis’ white wrist. 

“I want it,” he whines, and Mac moans loudly, unthinkingly, and there’s a sudden hush from the bar, or maybe he’s imagining it because then it’s white noise again as Dennis pulls him down and kisses him hard, and for the first time that night, on his mouth. Messy and uncoordinated, it’s almost not a kiss, Mac thinks, just two mouths opening up against each other. 

Dennis is going to have bruises everywhere, Mac realizes, as Dennis reaches down and tugs at his balls - which he knows, he knows drives Mac crazy, he figured it out years ago when Mac visited him in college, showed up at his dorm at three in the morning, high on glue or paint he can’t remember, and Dennis had looked at him with his wide eyes that he hadn’t yet grown into, lip pulled between his teeth and said, “You gonna run away again?” or something, Mac can’t remember, he’s not even sure that’s really what Dennis said it could just as well have been, “You got any addys?” or “You wanna smoke a joint?” but anyways, anyways Dennis is going to have bruises everywhere. On his hip bones, from the prints of Mac’s thumbs gripping him; on his throat, from the hard suck of Mac’s mouth; and maybe even littered across the flat shape of his ass, from the way the curve of his backside hits the desk with a sickening thud every time he fucks himself back on Mac’s fingers. 

“Give it to me,” he gasps out, and Mac shoves his fingers in deeper, harder, the push of his hand driving Dennis’ hips off the desk until he’s supported just by Mac’s arm slung behind his lower back. 

Mac holds him, crooking his fingers a little but not pulling them out just yet, just rubbing Dennis in slow circles from the inside out. “You shit,” Dennis breathes, clenching his teeth and looking away, “fuck, fuck you, I never let anyone else touch me like this, you son of a bitch.”

“Just take it, baby,” Mac says, pressing his fingers hard into the spot that makes Dennis’ vision white out and his neck roll back in languid pleasure. “So good, you’re so good, getting fucked open like this,” he tells him. “I’m gonna fuck you, now,” he says, and Dennis’ hands spasm where they’re clenched on his arms. 

“Yeah,” he says, tongue thick, looking a little dazed. “I can take it.”

Mac lowers him carefully back to the desk; his legs are shaking, and one heel drags across the side of the metal desk, screeching. Dennis shudders. “I want you to fuck me,” he says, as if that wasn’t clear. 

“I’m getting to it,” Mac promises, and he hauls him up again and turns him around so that he’s crooked over the desk. “I told you I would bend you over and fuck you up the ass, isn’t that right?”

Dennis moans, eyes sliding closed, pushing back mindlessly against Mac’s groin. “Gonna fuck me with my dress still on,” he purrs, and Mac presses his lips to the soft skin behind his ear. It’s not really a kiss. 

“Yeah, baby,” he says, and he slides the hem of the latex dress up and over the curves of Dennis’ body, leaves it bunched just above his hips. The thong is pink and lacy and he doesn’t bother taking it off, just slips it to the side and pulls the globes of Dennis’ ass apart so he can see the tight whorl of his hole. Dennis make a noise deep in his throat and bends lower, head falling to the crook of his elbow planted on the desk. 

“Fuck me, Mac,” he says, breath hitching a bit like a sob. “I want it, want you to split me open,” he breathes, slurring a little. “Shit.” Every time his hips undulate, Mac watches the tight clench of his hole shiver in motion. Dennis plants his hands on the desk. “I wanna feel your dick in my throat,” he says, eyes glittering as he looks back over his shoulder. 

Mac takes his cock, deeply flushed, in one hand and presses it against Dennis’ hole, feels Dennis relax and clench around him. He stops when just the head of his dick is inside, an unbelievably tight heat, and begins circling his hips the way Dennis likes. “You feel that?” 

“So good,” Dennis mutters, eyes clenched shut. He’d be fucking himself back on Mac’s dick if it weren’t for the way Mac has one hand on his hip and the other on his shoulder, holding him in place. “So fucking good,” he says, again. Mac flexes his hips and pushes in a little more, and watches a curl of pleasure writhe along Dennis’ spine, and then it’s easy to stop holding back, to curl his fingers around both of Dennis’ shoulders and shove him back on his cock with one sharp, swift move that knocks the breath from Dennis’ body and pulls a whine from the back of his throat. 

Mac fucks him with short, staccato thrusts, Dennis’ hand moving between his legs and the other planted on the desk, holding himself upright, which means that their bodies are pressed together from ankles to hipbones, and every so often Mac leans his forehead against Dennis’ flushed sweaty hairline and tells him, “You’re so fucking good, such a good fucking slut,” until Dennis slams his hand down on the desk, palm flat and wrist trembling, and Mac knows he’s coming because he goes suddenly silent and tense, and Mac fucks him through it, hard and fast like he likes, until he slumps forward bonelessly, spent, his thin back heaving and one hand reaching behind him to curl around Mac’s hipbone, saying “Don’t stop, baby boy, I want you to come inside me.” 

And for all of Mac’s fantasies about turning him around and putting his mouth to use, that’s what he wants too, wants to come inside Dennis and fill him up. He pushes, gently, at Dennis’ shoulder until he’s bent across the desk, body a new angle, and then Mac pumps into him, fucking in so tightly that he’s nearly mounting the round shape of Dennis’ ass, his thighs resting over the bent shape of his body. It must hurt, the desk must be digging into the soft fleshy bits of Dennis’ body, but he keeps the flat of his palm pressed to Mac’s side, fingers digging in as Mac fucks him, making these soft gasping noises into the back of his hand that he thinks Mac can’t hear. 

Mac can, though, and he leans back a little so he can watch, just for a few seconds, the shape of his cock fucking into Dennis, and that, combined with the sounds of Dennis being railed is enough to push him over the edge. He shuts his eyes and leans forward, chest fitting against Dennis’ back, planting one hand next to Dennis’ face and hips thrusting as something coils and snaps in him, coming with a feeling like a fist against his jaw. Beneath him, Dennis moans and shifts to press his mouth wetly against the skin of Mac’s forearm in something that’s not really a kiss. 

They’re both breathing hard, but the bar is otherwise silent; the others must have already gone home. Mac knows it’s not true, that time never really stops or stands still, no matter how much Charlie wishes it or how many times Mac wonders how God could have put him in this body, and can’t he have a different timeline, one where he’s normal and not all knotted up about boys with bony hips?

He knows that’s not true or possible, but here in this space, with Dennis still soft and pliant under him, he thinks maybe some people don’t know shit about time. In a minute, Dennis is going to stand up, and maybe he’ll smirk, shifting a little as Mac’s come starts to spill down his legs; or maybe he’ll look at Mac with flat eyes, one eyebrow cocked tauntingly; or maybe this will be one of the times where he can’t look at Mac at all, and he’ll pull the dress down over his thighs with fingers that aren’t trembling, goddamnit, they aren’t, and he’ll walk out and leave Mac to find his own way home. But right now, in this moment, Mac doesn’t want to think about any of that, not with Dennis’ heart thundering along with his own and the curl of a smile just visible on the edge of Dennis’ mouth. Mac shuts his eyes and he presses his mouth to a spot just on the side of Dennis’ jaw, where he can feel the muscles pulled taut, the shape of something that could be a smile. He presses his lips there, but it’s not really a kiss.

**Author's Note:**

> Thank you so much for reading! Feedback of all kinds loved and appreciated! <3


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